"Unlikely Knight: Monster Monpiece") is a card battle video game developed by Compile Heart for the PC and PlayStation Vita.

[12] A direct sequel, titled Monster Monpiece Naked for iOS and Android devices, was released on 29 May 2016[13] with services being terminated on 29 September 2017.

[15] In the world of Yafanir (ヤファニール) in which two enormous pillars known as the Hammers of God penetrate the Earth, a race known as the monster girls have come to coexist with humans.

[15][20] Trying to learn what master plan has been unleashed, May follows Elza, gathering treasure scattered across the world, and using the monster girls' Magus Quartz crystals to help on the way.

Imagery for the high level evolution forms of the Vampire, Kraken, Goblin, Cockatrice, Kobold, Skeleton, Titania, Bahamut, Fia, Brownie, Pegasus, Mandragora, Mau Sibau, Rafflesia, Death Scorpion, Phantom, and Tengu cards have been removed.

[19][21] The game reportedly sold through the majority of its initial 27,000 copy shipment, prompting Compile Heart to issue an apology for the lack of stock.

[41] Hardcore Gamer scored Monster Monpiece 3.5/5, praising all aspects of the game save for the "extreme rub" system, saying "Without the silly rubbing gimmick, Monpiece features deep, rewarding nuances, a bevy of customization options, fantastic production values and the ability to take one’s poured over deck online to square off against folks from around the world.

"[34] Tech-Gaming found the First Crush Rub mechanic "silly and unapologetically sophomoric", whilst praising the game's lore and single-player campaign, and taking issue with the design decision to limit the card augmentation until players unlocked a key through ad-hoc or network play.

They also praised the game's visual delivery noting that developer Compile Heart's previous console efforts have been decidedly mixed, giving Monster Monpiece a final rating of 84/100.

[35] Gamestyle regards the gameplay mechanics as a strong aspect of the game, however notes that there is a large cultural difference that pushes many boundaries in Western countries, where it may feel inappropriate for players to rub characters in a sexual manner.

[42] Colin Moriarty of IGN reviewed Monster Monpiece negatively, scoring the game a 4.9/10, criticizing the story, characters, upgrading system and environments.